pH, TDS and EC probes require calibration periodically to ensure accurate repeatable measurements. Calibration solutions are used to calibrate the probe. These are liquids which are manufactured specific to the calibration process.

pH, TDS and EC calibration solutions are available in a variety of units such as pH 7.0, pH 4.0 and pH 10.0, TDS 240ppm, TDS 342ppm and TDS 1000ppm. When calibrating, ensure the temperature of the solution and probe are as close as possible.

Reverse osmosis (RO) is a filtration method that removes many types of large molecules and ions from solutions by applying pressure to the solution when it is on one side of a selective membrane. The result is that the solute is retained on the pressurized side of the membrane and the pure solvent is allowed to pass to the other side.

Reverse osmosis is most commonly known for its use in drinking water purification from seawater, removing the salt and other substances from the water molecules.